1. Technical Field
Embodiments described herein relate generally to a semiconductor device and a method for producing the same, particularly, to a semiconductor device including a package structure and a method of manufacturing a semiconductor device.
2. Related Art
In a semiconductor device having a package structure in which a semiconductor chip is mounted on an island (also called die pad) of a lead frame and sealed with a sealing resin, it has heretofore been recognized that a large stress is applied at a corner part of the package structure. Therefore, technologies for preventing peeling of a lead which is an external connection terminal at the corner part receiving the large stress have been studied.
For example, Japanese Patent Application Laid-Open No. 2004-328015 and No. H11-214606 disclose a configuration in which an alignment pitch of the external connection terminals is reduced at a central part of a side and increased at a corner part. It is described that the configuration prevents peeling of the lead and the like at the corner part receiving the large stress and leads to high density of a semiconductor device by increasing the number of external connection terminals at the central part while enhancing reliability.
Japanese Patent Application Laid-Open No. H10-012790 discloses a configuration in which a bonding part for bonding to a bonding electrode of a mounting substrate and a dummy terminal having a width wider than a lead are provided at each of opposed sides of the lead provided on a lateral surface of a package structure.
Japanese Patent Application Laid-Open No. H06-224353 discloses that strength of a predetermined number of external connection terminals located at an end part is increased to be higher than that of medially-located external connection terminals, and a an area of the predetermined number of external connection terminals located at the end part for bonding to a substrate is increased to be larger than that of medially-located external connection terminals, so that bending of the external connection terminals at the end part is prevented or the medially-located external connection terminals are protected by the external connection terminals at the end part. It is described that the configuration improves connection reliability between the electronic components and the substrate by increasing the bonding strength.
Japanese Patent Application Laid-Open No. H04-363055 discloses a configuration in which a width of a lead is gradually reduced from a central part to an end part so as to reduce rigidity of the lead at the end part of a package structure as compared to the lead at the central part of each of sides of the package structure.